10.1-1

HSHQDC-10-R-00030-1011028-I - Radiation Detection Modules for the Geospatial Location Accountability and Navigation System for Emergency Responders (GLANSER) System

Topic Information

10.1-1 - Radiation Detection Modules for the Geospatial Location Accountability and Navigation System for Emergency Responsers (GLANSER) system

Award/Contract Number

HSHQDC-10-C-00160

Abstract

This project furthers the goal of enhancing the situational awareness of incident commanders by integrating radiation detectors in GLANSER. As stated in the GLANSER BAA 09-02, `there is an overarching requirement and a need for this capability to have interoperability and seamless integration amongst the other systems in the incident environment. In this manner, incident commanders and tactical decision makers will be able to enhance their overall situational awareness during an incident. In order to further the goal of seamless integration of radiation detectors in an incident environment this project will investigate the data available from current COTS radiation detectors, likely developments in radiation detectors over the near to mid term, and the requirements for transporting radiation data across the GLANSER network. Phase I will result in the definition of network interface node design requirements that will provide the full capability required for GLANSER integration as well as forming the basis for an eventual commercial product to fill this requirement. The team that Intelligent Optical Systems proposes for this investigation has unique recent experience with this subject matter as well as a broad background in the applicable areas of networking protocols, low power electronics, embedded software and radiation detection.

IAT has developed the 6LiFZnS(Ag) neutron detector for replacemen of 3He detectors providing neutron efficiency and gamma rejection comparable to 3He tube detectors. To increase neutron efficiency and reduce gamma events in our current detector, we propose the reduction of the ZnS(Ag)scintillation material to nano particles to enhance light transmission across the 6LiFZnS(Ag)layer. To further reduce gamma events and increase the abiltiy to separate neutron and gamma signals, we would further propose the replacement of the ZnS(Ag) scintillation material with an alternative scintillation material such as P47-Y2SiO5:Ce.

In the proposed program we plan to investigate novel semiconductor neutron detectors based on the wide bandgap, lithium containing compositions LiMgP LiMgAs and LiZnP. The goal of the program is to produce detector quality crystals and to demonstrate efficient thermal neutron detection, with the possibility of providing neutron gamma discrimination. We will examine the synthesis and purification of high quality starting materials and the growth of single crystals. We will evaluate the electronic, charge transport, and detection response characteristics of the materials that are produced. Thermal neutron detection studies and neutron gamma discrimination will be investigated. A compact low cost solid state thermal neutron detection system based on any of these materials would be a major breakthrough over conventional thermal neutron detectors, such as 3He tubes, which are currently in short supply. This development would open up many potential commercial applications for systems based on these detectors. Beyond nuclear non proliferation monitoring, neutron detection has important applications in several areas, including nuclear physics, oil exploration, materials characterization, biological research, nuclear waste characterization, health physics, and non-destructive evaluation.

In the proposed program, we plan to investigate novel semiconductor neutron detectors based on the wide bandgap lithium containing compositions LiGaSe2, LiGaTe2, LiInS2, and LiInSe2. The goal of the program is to produce detector quality crystals and to demonstrate efficient thermal neutron detection, with the possibility of providing neutron gamma discrimination. We will examine the synthesis and purification of high quality starting materials and the growth of single crystals. We will evaluate the electronic, charge transport, and detection response characteristics of the materials that are produced. Thermal neutron detection studies and neutron gamma discrimination will be investigated. A compact low cost solid state thermal neutron detection system based on any of these materials would be a major breakthrough over conventional thermal neutron detectors, such as 3He tubes, which are currently in short supply. This development would open up many potential commercial applications for systems based on these detectors. Beyond nuclear non-proliferation monitoring, neutron detection has important applications in several areas, including nuclear physics, oil exploration, materials characterization, biological research, nuclear waste characterization, health physics, and non destructive evaluation.

Neutron detection is one of the methods used in revealing illicit nuclear materials. Currently, there is an ongoing search for new and better neutron detectors prompted by anticipated shortages of He-3 that is used in many of the current detection systems. This effort proposes and investigation and development of a new thermal neutron and gamma scintillator. The scintillator belongs to already proven elpasolite crystal family. The main advantages of this material are due to avoidance of Cl (parasitic neutron absorption) and La (introduces radioactive isotopes) ions in the composition. This leads to a scintillator that is more efficient for thermal neutron detection and has lower intrinsic background. The material already showed that it is capable of discrimination between neutrons and gammas, a feature required in detectors to replace He-3 tubes. In addition, like other elpasolite crystals, the material should also provide excellent gamma energy resolution. We expect it to be better than 4 percent at 662 keV, which is almost twice as good as 7 percent for NaI:Tl (the most popular gamma scintillator). Phase I of the project will investigate in detail the properties of this material and provide optimal configuration for obtaining pulse shape discrimination and energy resolution.

Nuclear instrumentation for the detection of thermal neutrons relies heavily upon 3He because of its desirable nuclear properties and physical characteristics. The decline in production combined with increased demand has depleted the 3He stockpile and the supply of 3He is presently insufficient for US needs. The proposed effort seeks to address this problem by developing detector technology to help replace the existing generation of 3He-based instrumentation with detectors that use other neutron-sensitive material such as lithium. The Phase I prototype will comprise multiple sandwiched layers of converter/scintillator pairs connected to readout pulse processing electronics. Completion of the prototype and testing will demonstrate a path to attain at least 50 percent thermal neutron detection efficiency and gamma ray rejection rates of at least 10-5. The detectors will be designed to match the performance specification of existing 3He detectors in terms of overall neutron detection efficiency and gamma-ray rejection. Moreover, the instruments can be inexpensively scaled to cover large surface areas to be applied in both neutron scattering research as well as homeland security screening applications. Large detectors are most critical for advancement in these areas and face the greatest risk of cancellation or curtailment due to the shortage of 3He.

The polycrystalline ceramic proposed in this program will build upon existing MgAl2O4:Ce scintillator technology to explore alternative neutron detection materials as a near term replacement for large 3He tubes. The polycrystalline ceramic neutron detector can achieve high efficiency in capturing thermal neutrons due to its high concentration of active element. Its compact solid state design provides high stability and reduced volume/weight compared to 3He detector. The solid state neutron detector should have (1) better efficiency; 2) larger cross-sectional area; 3) thinner thickness; 4) lighter weight; and 5) reduced fabrication costs.

A Neutron detection device is an indispensable tool for power, medical, and defense applications. Proliferation of weapons of mass destruction such as nuclear weapons is a serious threat in today's world. Low cost, low power, high performance, rugged and portable neutron detection devices are highly desirable for these applications. Agiltron proposes an unprecedented fabrication and integration approach to make these solid-state neutron detectors commercially available at low cost for large-scale deployment. The success of this project will lead to the large-scale manufacture of these unmatched next generation neutron detectors.